“The era of imitating the West is over. Now we export Japanese culture,” said proud AKB48 creator/producer/svengali Yasushi Akimoto earlier this year. In addition to arranging a U.S. release for the group’s latest album, he told the Yomiuri Shimbun he’s entertaining offers to build similar girl groups in Thailand, China, Taiwan and Italy.

Many people in Japan consider Akimoto to be a musical genius. In actuality, he’s a marketing genius using a straightforward formula: teenage girls, modified schoolgirl uniforms, and dance routines that evoke both innocence and availability. It’s the happy Lolita aesthetic, which either totally squicks you out or makes you a really big fan of Japanese pop culture.

Akimoto started AKB48 in 2005 with the concept “idols you can meet.” The original target audience was the young, male, anime-obsessed otakus, who might otherwise be spending their money getting foot massages in one of Akihabara’s numerous cosplay cafes. Soon, AKBOta, as the superfans came to be called, were lining up outside the group’s theater to catch daily performances.

AKB48 is so popular in Tokyo it has spawned offshoots: SKE48, based in Nagoya, and and, most recently, NMB48 in Osaka. There’s also SDN48, a more adult-oriented group where all the girls are 20+. (The girls in AKB proper range from 15 to 24, with most of the girls being in their late teens.)

The group is divided into teams A, K, and B, with team captains presiding over each. Fans vote on who will be the “front” girls. Beyond that, the elements are simple: syrupy pop music, face-time with fans (handshaking events are part of AKB48 duties), and pretty young girls. Busloads of them.

Mr. Akimoto’s real genius is knowing the power of numbers. Keeping the group big is important. In addition to making promotional duties a breeze, it prevents individual members from becoming too famous and, thus, inaccessible or… perhaps, more importantly, irreplaceable. AKB48 may be the biggest female pop act in Japan, but-except for a few standout names-most of its members are only vaguely well-known. The girls also “graduate” as they age, or can be shuffled between teams or even sent back to the “research student” farm leagues, meaning, for most members, the ride won’t last much longer than high school. This Menudo-style endless churning of talent makes AKB48 the antithesis of other manufactured girl groups like, say, the Spice Girls, where-at some point-freshness is traded for nostalgia or, as Liz Lemon would say, members insist on clinging to youth and fame with their Gollum arms.

AKB48 members are also expected to cultivate extremely clean, girl-next-door images. This is in keeping with Japan’s ideal of the seijun-ha aidoru, or “pure idol.” In Japan, teen pop idols are expected to project an image of sweetness, positivity, and-most importantly-extreme purity. (We’re talking the kind of just-floated-in-on-a-cotton-candy-cloud level of sweetness and purity that, comparatively, makes Dakota Fanning look like a foulmouthed little slag.)

AKB48 members may pose in bikinis for fan magazines, or wrestle in lingerie in the occasional music video, but on their individual blogs, members switch to kid-sister mode, acting even younger than their stated ages, clutching teddy bears in webcam photos and breathlessly pledging to work harder for the fans.

Of course, as AKB48 members start to age and the alumni pool builds, it’s getting harder to keep everyone on-message.

Last month, fanblogs declared a state of “net turmoil” over the news that 22-year-old Rina Nakanishi, a recent Team A graduate, had changed her name to Riko Yamaguchi, shaved two years off her age, and launched a new career in AV, or porn.

“Really, AV!? wrote one fan on a Japanese blog. “Looking back at her time in AKB48, the image gap is so shocking. Even more than the other girls, she seemed so serious. “ Another expressed familial concern over Rina’s well-known lower back problems during her time with AKB48, worrying that her new line of work might exacerbate the issue.

Over on 2chan, (the Japanese big brother to 4chan) the otaku set ogled topless photos of Rina-turned-Riko, and engaged in a debate about whether or not she would use condoms in her debut, and how that decision would affect what remained of her AKB idol purity.

A few English fanblogs took a more cynical view, seeming to think that porn was a logical career move, seeing as Rina had already successfully cultivated a fanbase with lust in their hearts. One noted, with disgust, that Rina was receiving more attention now than she ever had as a squeaky-clean cog in the AKB machine: “The prospect of watching her squealing with feigned pleasure nude is unsurprisingly rather more enticing to idol fans than watching her squealing with feigned pleasure whilst bouncing around an Akihabara stage.”